Love me '98 M3! You can get a nice one for 11-12K and then save the rest. Get the sedan version, they are rare and I believe insurance is cheaper. Much more fun to drive than the 5 series!
Agree with Rob...have a nice car but you don't have to spend 20K. Do save some. You may not be able to buy rental property but you never know when you are going to stumble across a nice early 911 for 7 grand that just needs a new home
It has happened to me several times and I am glad I had some extra change laying around to snatch them up real quick. Much better than making payments on a Mazda.